Beginner question on assembly (for the SX28) - Electronic Circuits Projects Diagrams Free

Slimicus · 28th September 2007, 04:44 AM

Hello All,

Is there a way to pass a reference around to a particular PIN in assembly for the SX microcontroller?

I know I can declare a variable such as

Code:

LED_a    equ     RA.0
LED_b    equ     RA.1

But I want to be able to use generic variables such as

Code:

_param1      ds     1

to be able to pass "LED_a" to a subroutine using the call command. I'm pretty new at this, so there may be an entirely different method of doing this that I'm unaware of, but what I would LIKE to do is something similar to the following:

Code:

SetLedOutput 
            cje     _param1,#0,color_0
            cje     _param1,#20,color_1
            cje     _param1,#50,color_2
            cje     _param1,#254,color_3
            ret
color_0
            clrb  _param2 ;Hopefully _param2 contains a pin reference
            ret
color_1
            'some pwm code and conditional
            setb _param2
            ret
color_2
            'some pwm code and conditional
            setb _param2
            ret
color_3
            'some pwm code and conditional
            setb _param2
            ret

Then in my main program use it like this:

Code:

Main
            mov  _param2,LED_a
            mov  _param1,COLOR1
            call   SetLedOutput

            mov  _param2,LED_b
            mov  _param1,COLOR2
            call   SetLedOutput

Now, I'm not sure if this is even the proper way to attempt subroutines, as I said I'm still learning... but from what I read so far, I couldn't see a way to pass "parameters" to a subroutine directly, and if I use a macro, it will simply replicate that subroutine many times which could be costly in terms of program storage space... is there a better way to call subroutines with parameters?

Also the above code doesn't seem to work since I can't seem to move LED_a or LED_b into _param2, is there a way to accomplish this? Any help would be greatly appreciated

simrantogether · 28th September 2007, 07:44 AM

I'm sorry... please clarify what is SX microcontroller...

i've never seen such a kind of micro...

made by which co..?

Regards,

Simran..

Slimicus · 28th September 2007, 12:58 PM

Quote:

Originally Posted by simrantogether

I'm sorry... please clarify what is SX microcontroller...

i've never seen such a kind of micro...

made by which co..?

Regards,

Simran..

It's the SX28 made by Parallax, Inc

http://www.parallax.com/detail.asp?p...id=SX28AC/DP-G

blueroomelectronics · 28th September 2007, 02:59 PM

I've not used the Parallax assembler for over a year now, but they have some good tutorials for it on the tech-tools site http://www.tech-tools.com/

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28th September 2007, 04:44 AM	(permalink)
Slimicus	Beginner question on assembly (for the SX28) Hello All, Is there a way to pass a reference around to a particular PIN in assembly for the SX microcontroller? I know I can declare a variable such as Code: LED_a equ RA.0 LED_b equ RA.1 But I want to be able to use generic variables such as Code: _param1 ds 1 to be able to pass "LED_a" to a subroutine using the call command. I'm pretty new at this, so there may be an entirely different method of doing this that I'm unaware of, but what I would LIKE to do is something similar to the following: Code: SetLedOutput cje _param1,#0,color_0 cje _param1,#20,color_1 cje _param1,#50,color_2 cje _param1,#254,color_3 ret color_0 clrb _param2 ;Hopefully _param2 contains a pin reference ret color_1 'some pwm code and conditional setb _param2 ret color_2 'some pwm code and conditional setb _param2 ret color_3 'some pwm code and conditional setb _param2 ret Then in my main program use it like this: Code: Main mov _param2,LED_a mov _param1,COLOR1 call SetLedOutput mov _param2,LED_b mov _param1,COLOR2 call SetLedOutput Now, I'm not sure if this is even the proper way to attempt subroutines, as I said I'm still learning... but from what I read so far, I couldn't see a way to pass "parameters" to a subroutine directly, and if I use a macro, it will simply replicate that subroutine many times which could be costly in terms of program storage space... is there a better way to call subroutines with parameters? Also the above code doesn't seem to work since I can't seem to move LED_a or LED_b into _param2, is there a way to accomplish this? Any help would be greatly appreciated

28th September 2007, 07:44 AM	(permalink)
simrantogether	Is... I'm sorry... please clarify what is SX microcontroller... i've never seen such a kind of micro... made by which co..? Regards, Simran.. __________________ Simran.. 8051 Specialist..

28th September 2007, 02:59 PM	(permalink)
blueroomelectronics	I've not used the Parallax assembler for over a year now, but they have some good tutorials for it on the tech-tools site http://www.tech-tools.com/ __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com